Molded pulp article



.fi @n l Laws... L, @34%. F. CHAPLIN MOLDED PULP ARTICLE ori' nal FiledMaron 14, 1928 EYS .n $11 n V mw Mmm Patented Nov. 6, 1934 UNITED STATESPATENT OFFICE MOLDED PULP ARTICLE Merle P. Chaplin, Waterville, Maine,assignor, by

mesne assignments, to Fidelity Trust Company, Portland, Maine, acorporation of Maine Original application 4, 1931, Serial N0. 554,972

2 Claims.

This invention relates to molded pulp articles and to pulp moldingmachines for making such articles. Y

More particularly stated, the invention relates to the manufacture ofmulti-layer articles in pulp molding machines.

In the forming or manufacture of multi-layer articles it is sometimesdesirable, in order to secure a compact and impervious surface, toutilize a suitable material to fill in the spaces between the pulpfibers as the pulp is deposited on the forming die. Such material mustof necessity be finely divided and the individual particles must besmall enough to permeate the pulp deposit and lodge between the pulpfibers.

It is customary to mix such filling material with the pulp solution andthe passage of the water through the material, due to the suction on theforming die, causes a certain amount of the iilling material to beretained-in the formed article and lodge between the fibers thereof.However, a considerable amount oi the filling material is carriedcompletely through the formed article by the suction and is washed awayin the water that `is sucked through the forming die during the formingof the layer of pulp on the die. This is particularly true when thelling material is mixed with the pulp solution used to form a layer onthe wire screen or die face and another layer of pulp is then depositedon the iirst layer. Under such circumstances the water from the solutionlast deposited in passing through the ilrst layer of pulpcarries with ita considerable part oi the illlingv material.

With the above dilculties in mind, this invention has for its salientobject to provide a compact impervious molded pulp article.

Another objectgof the invention is to provide a molded pulp articlehaving filling or other like material positioned or located in theinside or unexposed portion of the molded article.

Further objects of the invention will appear fromthe followingspecification taken in connection with the drawing, which forms a partof this application, and in which Fig.l 1 is. an elevational viewsomewhat diagrami'itic of a machine adapted for use in making thearticle;

Fig. 2 is an enlarged sectional elevation showing Aa plurality of diesand a portion of the vat;

Fig. 3 is a sectional elevation taken substantially on line 3-3 of Fig.2;

Fig. 4 is a sectional elevation showing the article; and

.drawing there is shown Fig. 5 is a sectional elevation takensubstantially on line 5-5 of Fig. l.

This application is a division of application Serial No. 2611438, ledMarch 14, 1928 which eventuated into Patent No. 1,838,904, grantedDecember 29, 1931. The invention brieiiy described consists oi anarticle having a deposit of filling material disposed between the frontand back surfaces thereof. The method utilized to make the articleconsists of forming a layer of pulp deposit on and permeating the layerwith finely divided iilling material and then forming a further layer ofpulp on the back of the filling material. By forming the article in thismanner the filling material is not sucked through the screen or die facewith the water and, furthermore, is not exposed since there is a layero! p'ulp on both sides thereof.

In the particular form of apparatus or machine illustrated for carryingout the method, a vat is provided with compartments having differentsolutions therein and means is provided at a predetermined position inthe vat for so injecting the filling material that it will be depositedon the layer of on the die. The dies are mounted on a carrier and aremovable successively through the different .pulp solutions and in thefirst compartment receive a layer of one character oi pulp, then move tothe second compartment to receive another layer and also the fillingmaterial, and after receiving the filling material the dies receive afurther layer of pulp.

Further details of the invention will appear from the followingdescriptio In the particular machine illustrated in the a carrier 10having a hub 11, conduits 12 extending radially from the hub, andforming dies 13 of any suitable constuction mounted on the outer ends ofthe cond ts.

As shown in Fig. 3, the conduits and dies are arranged side by side insets of three, shown at A, B and C, and the carrier is provided withside walls or faces .f4 and 15 outside the conduits and dies A and C.The die faces of the dies 13 are perforated and through the hub 1 1 thearms 12 are connected to a suitable source of suction so that as thedies pass through the vat pulp is deposited thereon from the pulpsolutions.

The carrier and dies are mounted above a vat 20 having a partition 21forming two compartments, X and Y. As shown in Fig. 2, the partition 21has extending laterally therefrom into the compartment X, a ledge orshelf 22 preferably 110 pulp already deposited 50 slightly curved orarcuate to conform to the arcuate path of movement of the dies. Ifdesired, the partition may also have formed thereon and disposed abovethe shelf, side walls 23 which with the shelf 22 form a trough throughwhich the dies pass, the partition being provided with an opening abovethe shelf to permit the passage of the carrier and dies.

As the dies pass through the solution in the compartment X, a layer ofpulp is deposited thereon, and since the trough formed by the walls 23and the shelf 22 enclose a comparatively limited amount of pulpsolution, substantially all of the pulp solution in the trough isdeposited on the dies, thus preventing its being carried with the diesand carrier into the compartment Y.

If desired, the compartment X may have one character of solutiontherein, such for instance, as a high grade or light colored pulp, andthe compartment Y may have a coarser or darker grade of pulp.

There is positioned at a predetermined point in the compartment Y, ashelf or ledge 30 having connected thereto conduits 31, 32 and 33 spaceda distance apart corresponding to the conduits A, B and C. The upperends, of the conduits are tapered, as shown in Fig. 2, at 35 to formnozzles.

Each conduit communicates with a valve casing 36 having a pair ofchambers 37 and 38 therein which are adapted to commnuicate with eachother through a port 39. The communication through the port 39 iscontrolled by a valve 40 which in turn is controlled by a tappet leveror rod 41. The, levers 4l are controlled by cams' 42 mounted onia camshaft 43. Each chamber 37 has connected thereto a conduit 45 which inturn is connected to a supply of suitable filling material and thismaterial is preferably pumped under pressure into the conduits 45.

The cam shaft 43 is rotated at such a speed that the valves 40 will beopened at the periods in -the cycle of revolution of the carrier 10 whena set of dies is positioned above the nozzles 35.A It is obvious thatthe shelf, conduits and nozzles can be located at any desired point inthe compartment Y or, if desired, in another compartment, 'so that thefilling material will be deposited on the die and layer of pulp thereonat any desired period in the cycle of operation.

'I'he machine operates in the following manner: As the dies pass throughthe compartment X a layer of pulp from the solution therein is depositedon the dies. When the dies pass overv the shelf 22 into compartment Y anintermixtureof the pulp from the compartments X and Y will be depositedthereon in interfelted relation and then a small amount of pulp from thecompartment Y will be deposited. When the dies reach a position over thenozzles 35, the valves 40 will be opened and a mixture of fillingmaterial will be deposited already formed on the dies. Then, as the diescontinue tomove through the compartment Y, an outer layer of pulp fromcompartment Y will be deposited on and cover the layer of fillingmaterial. The with the fibers previously deposited.

It is obvious that the amount of suction and the location of thepartition 21 can be so determined that sufcient layers of pulp will bedeposited on the dies prior to the depositing thereion of the fillingmaterial to prevent the material being sucked through the layer of pulpand through the die face with the water which is removed from thedeposit by the suction.-

It will be evident from the method and apparatus above described thatarticles formed thereby will have inner and outer layers of pulp and adeposit of filling material positioned Abetween md concealed by theinterfelted inner and outer ayers.

Although one specific embodiment of the invention has been particularlyshown and described, it will be understood that the invention is capable'of modification and that changes in the construction and in thearrangement of the various cooperating parts may be made withoutdeparting from the spirit 'or scope of the invention, as expressed inthe following claims.

What I claim is:

1. A molded article formed from pulp fiber and having interlaced fibersand having finely divided, comminuted ller material filling theinterstices between the fibers in the intermediate portion of thearticle, the said filler material not interfering with the interlacingof the bers on opposite sides of the zone of filler material.

2. A molded pulp article having successive deposits of fibers and havingincorporated in the intermediate deposits thereof comminuted flllermaterial located in the interstices of the deposits, the size and amountof filler being controlled to permit continuous interfelting of thefibers of the article, there being no distinct line of cleavage. l

. MERLE P. CHAPLIN.

on the layer of pulp outer layer will be interfelted

